Control device of supercharger-equipped engine

Abstract

A throttle device is provided at the intake passage downstream of a compressor, a purge passage is connected to the intake passage upstream from the compressor, a purge valve is provided in the purge passage, an inlet valve is provided upstream of a connection position between the purge passage and the intake passage, and an air flow meter is provided in the intake passage upstream of the inlet valve. An electronic control device: calculates a target purge flow rate (TPFR) for vapor to the intake passage while the throttle device is controlled to a prescribed opening degree and the inlet valve is controlled to a target intake opening degree (TIOP); calculates the target purge opening degree to ensure the TPFR; controls the purge valve to the TIOP and corrects the TIOP by the TPFR; and controls the inlet valve by the corrected TIOP.

1 . A control device of a supercharger-quipped engine, the engine comprising:
 a supercharger provided in an intake passage and an exhaust passage of the engine and configured to increase pressure of intake air in the intake passage,   the supercharger including a compressor placed in the intake passage, a turbine placed in the exhaust passage, and a rotary shaft connecting the compressor and the turbine to cause the compressor and the turbine to integrally rotate;   an intake amount regulating valve provided in the intake passage downstream from the compressor and configured to have an adjustable opening degree to regulate an intake amount of air flowing through the intake passage;   a gas passage connected to the intake passage upstream from the compressor and configured to supply a predetermined gas to the intake passage;   a gas flow regulating valve provided in the gas passage and configured to have an adjustable opening degree to regulate a gas flow rate in the gas passage;   an inlet valve provided in the intake passage upstream from a junction of the gas passage with the intake passage and configured to have an adjustable opening degree to restrict the intake amount of air to be sucked in the intake passage;   an intake flow detecting unit configured to detect the intake amount of air flowing through the intake passage upstream from the inlet valve; and   a control unit configured to control at least the intake amount regulating valve, the gas flow regulating valve, and the inlet valve,   wherein the control unit is configured to:   while controlling the intake amount regulating valve to a predetermined opening degree and controlling the inlet valve to a target intake opening degree according to an operating state of the engine,   calculate a target gas flow rate to be supplied to the intake passage according to the operating state of the engine;   calculate a target gas flow rate opening degree for securing the target gas flow rate based on predetermined function data;   control the gas flow regulating valve to the target gas flow rate opening degree;   correct the target intake opening degree based on the target gas flow rate; and   control the inlet valve based on the corrected target intake opening degree.   
     
     
         2 . The control device of a supercharger-quipped engine according to  claim 1 , wherein the control unit is configured to:
 measure an actual gas flow rate to be supplied from the gas passage to the intake passage based on the intake amount detected by the intake flow detecting unit;   calculate an opening degree correction value of the gas flow regulating valve or the inlet valve based on the measured actual gas flow rate so that the actual gas flow rate becomes equal to the target gas flow rate; and   update the target gas flow rate opening degree in the function data based on the calculated opening degree correction value or update the target intake opening degree of the inlet valve.   
     
     
         3 . The control device of a supercharger-quipped engine according to  claim 1 , further comprising:
 an EGR passage configured to allow a part of exhaust gas discharged from the engine to the exhaust passage to flow as EGR gas into the intake passage to return to the engine,   the EGR passage including an inlet connected to the exhaust passage downstream from the turbine and an outlet connected to the intake passage upstream from the compressor and downstream from the inlet valve; and   an EGR valve configured to have an adjustable opening degree to regulate an EGR gas flow rate in the EGR passage,   wherein the control unit is configured to control at least the intake amount regulating valve, the gas flow regulating valve, the inlet valve, and the EGR valve, and   the control unit is configured to:
 while controlling the intake amount regulating valve to the predetermined opening degree and controlling the inlet valve to the target intake opening degree according to the operating state of the engine, and further controlling the EGR valve to a target EGR opening degree according to the operating state of the engine, 
 calculate the target gas flow rate to be supplied to the intake passage according to the operating state of the engine; 
 calculate the target gas flow rate opening degree for securing the target gas flow rate based on the predetermined function data; 
 control the gas flow regulating valve to the target gas flow rate opening degree; 
 correct the target intake opening degree based on the target gas flow rate; and 
 control the inlet valve based on the corrected target intake opening degree. 
   
     
     
         4 . The control device of a supercharger-quipped engine according to  claim 1 , wherein
 the control unit is configured to:
 when controlling the gas flow regulating valve to fully close, controlling the inlet valve to fully open, and further controlling the intake amount regulating valve to an arbitrary controlled opening degree so that intake air passes through the intake amount regulating valve at sonic velocity, 
 obtain an actual opening degree of the intake amount regulating valve based on the intake amount detected by the intake flow detecting unit and a predetermined basic expression; 
 learn an opening degree correction value of the intake amount regulating valve from a difference between the obtained actual opening degree and the controlled opening degree; and 
 correct control of the intake amount regulating valve based on the learnt opening degree correction value; and 
   the control unit is configured to:
 after correcting the control of the intake amount regulating valve based on the learnt opening degree correction value of the intake amount regulating valve, 
 when controlling the gas flow regulating valve to fully close and controlling the inlet valve to close to the arbitrary controlled opening degree, 
 obtain an actual opening degree of the inlet valve based on the intake amount detected by the intake flow detecting unit and the basic expression; 
 learn an opening degree correction value of the inlet valve from a difference between the obtained actual opening degree and the controlled opening degree of the inlet valve; and 
 correct control of the inlet valve based on learnt opening degree correction value. 
   
     
     
         5 . A control device of a supercharger-quipped engine, the engine comprising:
 a supercharger provided in an intake passage and an exhaust passage of the engine and configured to increase pressure of intake air in the intake passage,
 the supercharger including a compressor placed in the intake passage, a turbine placed in the exhaust passage, and a rotary shaft connecting the compressor and the turbine to cause the compressor and the turbine to integrally rotate; 
   an intake amount regulating valve provided in the intake passage downstream from the compressor and configured to have an adjustable opening degree to regulate an intake amount of air flowing through the intake passage;   an evaporated fuel treatment device configured to collect evaporated fuel generated in a fuel tank into a canister once and purge the evaporated fuel to the intake passage through a purge passage provided with a purge valve configured to have an adjustable opening degree,
 the purge passage including an inlet connected to the canister and an outlet connected to the intake passage upstream from the compressor; 
   an inlet valve provided in the intake passage upstream from the outlet of the purge passage and configured to have an adjustable opening degree to restrict the intake amount of air to be sucked into the intake passage;   an intake flow detecting unit configured to detect the intake amount of air flowing through the intake passage upstream from the inlet valve; and   a control unit configured to control at least the intake amount regulating valve, the purge valve, and the inlet valve,   wherein the control unit is configured to:
 when controlling the purge valve to fully close, controlling the inlet valve to fully open, and further controlling the intake amount regulating valve to an arbitrary controlled opening degree so that intake air passes through the intake amount regulating valve at sonic velocity, 
 obtain an actual opening degree of the intake amount regulating valve based on the intake amount detected by the intake flow detecting unit and a predetermined basic expression; 
 learn an opening degree correction value of the intake amount regulating valve from a difference between the obtained actual opening degree and the controlled opening degree; and 
 correct control of the intake amount regulating valve based on the learnt opening degree correction value, and 
   the control unit is configured to:
 after correcting the control of the intake amount regulating valve based on the learnt opening degree correction value of the intake amount regulating valve, 
 when controlling the purge valve to fully close and controlling the inlet valve to close to the arbitrary controlled opening degree; 
 obtain an actual opening degree of the inlet valve based on the intake amount detected by the intake flow detecting unit and the basic expression; 
 learn an opening degree correction value of the inlet valve from a difference between the obtained actual opening degree and the controlled opening degree of the inlet valve; and 
 correct control of the inlet valve based on the learnt opening degree correction value. 
   
     
     
         6 . The control device of a supercharger-quipped engine according to  claim 4 , wherein the control unit is configured to:
 after correcting the control of the intake amount regulating valve based on the learnt opening degree correction value of the intake amount regulating valve and correcting the control of the inlet valve based on the learnt opening degree correction value of the inlet valve,   obtain, as a gas flow rate change rate, a change rate of the intake amount detected by the intake flow detecting unit when the gas flow regulating valve is controlled to a predetermined second opening degree larger than a predetermined first opening degree, with respect to the intake amount detected by the intake flow detecting unit when the gas flow regulating valve is controlled to the first opening degree;   obtain an actual opening degree of the gas flow regulating valve based on the gas flow rate change rate and the basic expression;   learn an opening degree correction value of the gas flow regulating valve from a difference between the obtained actual opening degree and the second opening degree of the gas flow regulating valve; and   correct control of the gas flow regulating valve based on the learnt opening degree correction value.   
     
     
         7 . The control device of a supercharger-quipped engine according to  claim 4 , wherein the control unit is configured to compare the obtained actual opening degree of the inlet valve with a predetermined reference value for an opening degree of the inlet valve to diagnose abnormality of the inlet valve. 
     
     
         8 . The control device of a supercharger-quipped engine according to  claim 6 , wherein the control unit is configured to compare the obtained actual opening degree of the gas flow regulating valve with a predetermined reference value for an opening degree of the gas flow regulating valve to diagnose abnormality of the gas flow regulating valve. 
     
     
         9 . The control device of a supercharger-quipped engine according to  claim 2 , wherein the control unit is configured to compare the actual gas flow rate measured based on the intake amount detected by the intake flow detecting unit with a predetermined reference value to diagnose abnormality of the gas flow regulating valve or abnormality of the inlet valve. 
     
     
         10 . The control device of a supercharger-quipped engine according to  claim 1 , wherein the control unit is configured to:
 measure an actual gas flow rate to be supplied from the gas passage to the intake passage based on the intake amount detected by the intake flow detecting unit; and   compare the measured actual gas flow rate with a predetermined reference value to diagnose abnormality of the gas flow regulating valve or abnormality of the inlet valve.   
     
     
         11 . The control device of a supercharger-quipped engine according to  claim 1 , wherein
 the control unit is configured to:
 when controlling the gas flow regulating valve to fully close, controlling the inlet valve to fully open, and further controlling the intake amount regulating valve to an arbitrary controlled opening degree so that intake air passes through the intake amount regulating valve at sonic velocity, 
 obtain an actual opening degree of the intake amount regulating valve based on the intake amount detected by the intake flow detecting unit and a predetermined basic expression; 
 learn an opening degree correction value of the intake amount regulating valve from a difference between the obtained actual opening degree and the controlled opening degree; and 
 correct control of the intake amount regulating valve based on the learnt opening degree correction value; and 
   the control unit is configured to:
 after correcting the control of the intake amount regulating valve based on the learnt opening degree correction value of the intake amount regulating valve, 
 when controlling the gas flow regulating valve to fully close and controlling the inlet valve to close to the arbitrary controlled opening degree, 
 obtain an actual opening degree of the inlet valve based on the intake amount detected by the intake flow detecting unit and the basic expression; and 
 compare the obtained actual opening degree of the inlet valve with a predetermined reference value for the opening degree of the inlet valve to diagnose abnormality of the inlet valve. 
   
     
     
         12 . The control device of a supercharger-quipped engine according to  claim 4 , wherein the control unit is configured to:
 after correcting the control of the intake amount regulating valve based on the learnt opening degree correction value of the intake amount regulating valve and correcting the control of the inlet valve based on the learnt opening degree correction value of the inlet valve,   obtain, as a gas flow rate change rate, a change rate of the intake amount detected by the intake flow detecting unit when the gas flow regulating valve is controlled to a predetermined second opening degree larger than a predetermined first opening degree, with respect to the intake amount detected by the intake flow detecting unit when the gas flow regulating valve is controlled to the first opening degree;   obtain an actual opening degree of the gas flow regulating valve based on the gas flow rate change rate and the basic expression; and   compare the obtained actual opening degree of the gas flow regulating valve with a predetermined reference value for the opening degree of the gas flow regulating valve to diagnose abnormality of the gas flow regulating valve.   
     
     
         13 . The control device of a supercharger-quipped engine according to  claim 5 , wherein the control unit is configured to compare the obtained actual opening degree of the inlet valve with a predetermined reference value for an opening degree of the inlet valve to diagnose abnormality of the inlet valve.